Hydraulic broaching machine



K. C. MONROE HYDRAULIC BRoAcHING MACHINE Sept. 19,I 1939 Filed Oct. 18,1937 2 Sheets-Sheet 2 Mm. \l N -\\\\\\\\\\\\\\\\x imm- Patented Sept.19, 1939 PATENT OFFICE HYDRAULIC BROACHING MACHINE Kenneth C. Monroe,Hudson, Mass., assigner to The Lapointe Machine Tool Company, Hudson,Mass., a corporation of Maine Application October 18,

3 Claims.

This invention relates to a hydraulic breaching machine of the typewhich is operated by a reversible discharge pump, such as the pump shownin West Patent No. 1,722,832. When such a b-reaching machine is made oflarge size and is designed for heavy work, the operating pump must becorrespondingly large and heavy, and the manual reversal of the pumptwice for each breaching operation causes fatigue of the operator ifcontinued over an extended period of time.

It is the general object of my invention to provide a breaching machinehaving mechanism for reversing the pump by power but under the continuedcontrol of the operator.

A further object is to provide a breaching machine having controlapparatus which becomes inoperative as soon as released by the operatorand which normally leaves the machine free for manual control.

In the preferred form of my invention, the control apparatus is sodesigned and constructed that the machine may be stopped manually at anypoint in its working stroke and that it will be stepped automatically ateach limit of breaching movement. Y

A further object of my invention is to provide control apparatus forreversing a pump in a hydraulic breaching machine, which apparatus maybe placed in any desired or convenient location with respect to otherparts of the machine and in reference toother duties of the operator.

My invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly pointed out inthe appended claims.

A preferred form of the invention is shown in the drawings, in whichFig. 1 is a diagrammatic side elevation, partly is section, showingparts of a hydraulic breaching machine embodying my invention;

Fig. 2 is a side elevation, partly in section, showing the controlapparatus on an enlarged scale; and

Figs. 3 and 4 are detail sectional side elevations showing certain partsappearing in Fig. 2 but in different working positions.

Referring to the drawings, I have shown my invention embodied in abreaching machine operated by a reversible discharge pump. The breachingmachine is indicated as having a main hydraulic cylinder I0 in which apiston I I is vertically slidable. The piston II is connected by apiston rod I2 to a ram or slide I4having an offset portion I5 to which abreach B is detachably secured. The machine is indicated as being 1937,Serial N0. 169,581

of the pull-down type, in which the breach is drawn downward through thework during the breaching operation.

The main cylinder I0 is connected by pipes 20 and 2| to upper and lowerports in a reversible discharge pump P, which ports serve alternately asintake or discharge. The details of the pump connections and its. methodof operation form no part of the present invention, which relatesparticularly to the power actuation of the pump reversing mechanismunder manual control. The direction of discharge of the pump P iscontrolled by a sliding rack bar 25 engaging a gear 26 which in turncontrols the position of a rocker plate inside of the pump casing. Forfurther information as to the details of the pump P, reference is madeto--the West patent previously cited.

Ihe rack bar 25 is connected by a link 2l, lever 28 and link 29 to abell crank 30, and the horizontal arm of the bell crank is connected bya link 3l to the lower end of a stop red 32, provided with upper andlower adjustable stop collars 33 and 34.

A block 35 is mounted at the upper end of a rod 36 carried by theextension I5 of the ram or slide I4. As the block 35 engages one of theco1- lars 33 or 34, the rack bar 25 will be moved to place the pump P inneutral position, thus bringing the slide I4 to rest at its upper orlower limit of travel.

The bell crank 30 is also connected through a link 31 to a hand lever 40by which the pump P may be manually controlled or reversed. When thehand lever 40 is moved downward, the breach B will be given a downwardor working stroke and when the hand lever is moved upward, the slide I4will be returned to upward position.

In order that the mechanism of the pump P may be additionally moved bypower under certain conditions, I connect the handle 40 by a link 4I(Fig. 2) to the upper end of a piston rod 42 having a piston 43 mountedthereon and slidable in a cylinder 44.

The upper and lower ends of the cylinder 44 are connected by pipes 46and 41 to spaced ports in a valve casing 50 enclosing a valve chamber 5I.

' A piston valve 52 is slidable in the valve chamber 5I and has spacedpiston elements 53 and 54.

The piston 52 is mounted on a piston rod 56 extending through suitableglands in the ends of the valve casing 50. One end of the red 56 has apin and slot connection to a control lever 60. Springs 6I and 62 aremounted on the red 56 which is provided with adjustable cellars 63against which the springs abut.

An air or hydraulic pressure pipe 'l0 is. connected to the middleportion of the chamber 5l, and exhaustI pipes 1| connects both ends ofthe chamber 5I to the atmosphere.

When the handle is free, the springs 6l and 62 cooperate to move thepiston valve 52 to its middle or neutral position in which both pipes 46and 47 are connected to the atmosphere as indicated in Fig. 4. Thisleaves the piston 43 free from pressure, so that the hand lever 40 maybe freely shifted, either manually or by the knockoif mechanism.

Assuming that the machine is stopped with the slide in raised positionand with the pump P in neutral, a working or down stroke may be startedby sluiting the lever 60 to the left as indicated in Fig, 2. Thisconnects the pressure pipe 'i9 through the upper pipe 46 to the upperend of the cylinder 44, and connects the lower end of the cylinderthrough the pipe 41 to the atmosphere. The lever 4i) is then moveddownward under power, shifting the pump P from neutral to workingposition. The working or down stroke of the broach then takes place.

-As soon as the down stroke is started, the operator may release thecontrol lever 60, whereupon the lever 6i! and piston valve 52 connectedthereto are immediately returned to the mid or neutral position shown inFig. 4. At the end of the down or working stroke the handle lever 40 andthe pump reversing mechanism are returned to neutral position by theknock-off mechanism.

In order to thereafter return the ram or slide I4 to its up position,the control lever 69 is shifted to the right to the position shown inFig. 3, admitting pressure to the lower end of the cylinder 44 andconnecting the upper end of the cylinder 44 to the atmosphere. The handlever 4D is thus moved upward, shifting the pump reversing mechanism toup-stroke position. The control lever may be released as soon as the upstroke has started and will be automatically returned to neutralposition, all as previously described.

It will be noted that all pressures on the piston 52 are balanced at alltimes, so that there is no displacing force.

If the lever Gl] is not released by the operator before the end of an upor down stroke of the slide i4, no harm is done, as the main cylinderIt! and piston H are many times larger and more powerful than thecylinder 44 and piston 43 and will readily displace the piston 43against any pressure which is being exerted thereon.

Similarly, if the operator moves the lever 68 in the wrong directionfrom neutral position, no harm will be done. If the broaching machinehas been brought to rest at the lower end of the stroke, the block 35will be in engagement with the collar 34 and will prevent downwardshifting of the lever 40, even if the control mechanism is shifted tothe position shown in Fig. 2. Similarly no upward movement of the lever4S can take place when the slide has been stopped in upper position byengagement of the block 35 with the collar 33.

I have thus provided mechanism by which the discharge mechanism of areversible pump may be moved by power under control of the operator butwill at the same time be free for direct manual operation as soon as thecontrol lever is released and at any point in the stroke. Furthermore,my improved control mechanism permits the usual knock-off devices of thebroaching machine to operate in the usual manner and to bring thebroaching slide to rest and the pump 'to neutral position at the end ofeach up or down stroke.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:

l. A hydraulic broaching machine operated by a reversible discharge pumpand having a member connected to the discharge-reversing mechanism formoving said mechanism manually, pressure-operated means to move saidmechanism by power, manually operated control means for saidpressure-operated means, and automatic means to neutralize said pressureoperated means as soon said control means is manually released.

2. A hydraulic broaching machine operated by a reversible discharge pumpand having a member connected to the discharge-reversing mechanism formoving said mechanism manually, pressure-operated means to move saidmechanism by power, and manually operated control means for saidpressure-operated means, said control means including a spring-actuatedvalve mechanism automatically returnable to initial mid position andthereby rendering said pressure-operated means inoperative when saidvalve mechanism is manually released.

3. A hydraulic breaching machine operated by a reversible discharge pumpand having a member connected to the discharge-reversing mechanism formoving said mechanism manually, a cylinder and piston connected to movesaid reversing mechanism by power, a valve for said cylinder by whichpressure can be admitted at either end of said cylinder while the otherend is connected to atmosphere, said valve when in mid positionconnecting both ends of said cylinder to atmosphere, a manualy-operatedcontrol device for said valve, and automatic means to move said valve tomid position when said control means is manually released.

KENNETH C. MONROE.

